Joel Strand

First-order sideband transitions with flux-driven asymmetric transmon qubits

We demonstrate rapid, first-order sideband transitions between a superconducting resonator and a frequency-modulated transmon qubit. The qubit contains a substantial asymmetry between its Josephson junctions leading to a linear portion of the energy band near the resonator frequency. The sideband transitions are driven with a magnetic flux signal of a few hundred MHz coupled to the qubit. This modulates the qubit splitting at a frequency near the detuning between the dressed qubit and resonator frequencies, leading to rates up to 85 MHz for exchanging quanta between the qubit and resonator.

Process verification of two-qubit quantum gates by randomized benchmarking

We implement a complete randomized benchmarking protocol on a system of two superconducting qubits. The protocol consists of randomizing over gates in the Clifford group, which experimentally are generated via an improved two-qubit cross-resonance gate implementation and single-qubit unitaries. From this we extract an optimal average error per Clifford operation of

TUNABLE TRANSMON CIRCUIT ASSEMBLY

0.0936

Demonstrated control of a Transmon using a Reciprocal Quantum Logic digital circuit - Part 1

. We also perform an interleaved experiment, alternating our optimal two-qubit gate with random two-qubit Clifford gates, to obtain a two-qubit gate error of

Superconducting tunable coupler

0.0653

Exponential-Off Qubit Couplers

. We compare these values with a two-qubit gate error of

Protecting quantum information from noise – a passive approach

\ensuremath{\sim}0.12

ZZZ coupler for native embedding of MAX-3SAT problem instances in quantum annealing hardware

obtained from quantum process tomography, which is likely limited by state preparation and measurement errors.